Do we have any theory that covers a possibility of the big bang's origin? This seems like the most difficult question of all. Logic tells us that every effect has a cause. But every cause must be the ...

according to string theory every universe is a large brane and big bang is a event which takes place when two branes collide with each other. if our universe brane collides with another brane there ...

Extrapolation of the expansion of the Universe backwards in time using general relativity yields an infinite density and temperature at a finite time in the past.
If the matter contained within our ...

So far I know, quantum fluctuations happen inside the vacuum which resides in the space-time. So, can it happen outside space-time? Because, one proposition suggest, big-bang was result of some kind ...

Ok, let me make myself clear. I saw all the other questions related to the question, but none of them actually asks the question the way I would put it and therefore no one answers it the way I want ...

The reason I am asking this question is because if all points in space observe recession of galaxies the same as we do from Earth, the universe would have to be infinite (or a closed sphere in 4D or ...

I've read several articles about observable Universe, Universe and Hubble volume, including Wikipedia article and references on it, and I wondered: Is there a formal, rigorous definition in physics of ...

I've read an analogy that finding iron-rich galaxies just 900 years after the Big Bang is like finding an old man in a crib in a nursery. We just recently found a supermassive black hole 12 billion ...

The universe was at its hottest when it was at its smallest. As the universe expands, it gets cooler.
Is the expansion of the universe the direct cause the cooling?
I suppose it would be more clear ...

I understand that the history of our universe began with an explosion - the Big Bang. Now, I saw a comment in some old post, that "the universe has no center". Is that true? If there was initially a ...

Expansion of our universe is accelerating. This means that it was expanding less rapidly in the past.
Is in accordance with the laws of physics a model of accelerating universe in which the rate of ...

A news story is going viral on social media networks claiming that two physicists have found a way to eliminate the Big Bang singularity, or in layman's terms (as claimed by many sensationalist news ...

Wasn't the density of the universe at the moment after the Big Bang so great as to create a black hole? If the answer is that the universe/space-time can expand anyway what does it imply about what ...

I just asked this astronomy question about how far away the light is that would show us the beginning of time, the Big Bang.
Some answers claim that the light I ask about doesn't exist, because "The ...

Let's suppose that I am on Point A with a light-beam launcher. My goal is to launch a beam of light to Point B, which is about 8,000 quadrillion light years away. My friend named Jack is at Point B ...

How much energy and heat were produced by the big bang? I'm reading Bill Bryson's Short history.... He mentioned a point that to forage light elements like hydrogen, helium and lithium into elements ...

Why is it necessary for spacetime and energy/matter to begin together at spacetime = 0? Would the universe look any different today if energy/matter had appeared some time after spacetime had begun ...

Given what we know about space, time and the movement of galaxies, have we or can we determine what our position is in relation to the projected location of the Big Bang? I've read some introductory ...

Is the expansion of the space between the galaxies caused by stretching of existing space or the creation of new space?
The fact that the energy content remains constant, and is therefore not being ...

I always thought the uniformity in the temperature of the CMB was supposed to be expected, since it's a much more probable initial condition for the universe. I finally found someone explaining what I ...

(I asked this question in Philosophy.SE; but I was advised to direct it here, despite it is, in my opinion, somewhat too speculative for physics.SE).
High entropy generally means high disorder; and ...